<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<script type="text/javascript">
			window.onload = function(){//父节点
				var blue = document.getElementsByTagName('li')[1];
				console.log(blue.parentNode);//<ul>
				console.log(blue.parentNode.parentNode);//<body>
				console.log(blue.parentNode.parentNode.parentNode);//<html>
				console.log(blue.parentNode.parentNode.parentNode.parentNode);//Document
				console.log(blue.parentNode.parentNode.parentNode.parentNode.parentNode);//null
			}
		</script>
		<title></title>
	</head>
	<body>
	</body>
</html>
